Make a hollow silicon ball with a silicon tube through it that has Dacron mesh ends. Suture one Dacron end into an artery and one into a vein in the abdominal cavity near the aorta (perhaps between the kidneys). The pressure in the abdominal cavity varies constantly so if the ball were filled with air
it would be constantly changing its shape. This change in shape could either use the same technology as a Rolex to generate electricity or the new technology that drives energy from silicon between conductive plates as it compresses (whichever is more efficient). This energy could be used to chromatically scan the O2 concentration in the arteries as it passes through the sutured in tube, also temperature, respiratory rate, heart rate, perhaps even blood glucose or ETOH. It could be programmed with a unique identifier sequence and transmit using a technology like Bluetooth. The identifier code could be used to identify you at the bank or the mall or work, and could differentiate between clients in a hospital setting. Nurses would not have to constantly monitor such tedious things and doctors could have a better understanding of the real-time effect of treatment. I figure this technology could also power devices like pacemakers and Deep Brain Stimulation devices. People could have them implanted at birth.

Please tell me more about the two technologies:
"as a Rolex to generate electricity or the new technology that drives energy from silicon between conductive plates as it compresses" so that we may help determine which is the more efficient means - or so that I can use these other technologies for other applications.